Timing Gear Train, Front Cover & Camshaft

2.DISMANTLING a)Press the camshaft out of the gear then remove the key and thrust plate from the camshaft.

3.INSPECTION AND REPAIR

a)Inspect the cam lobes and camshaft journals for wear to specifications.

b)Inspect the oil pump drive gear, if excessive wear is found, the camshaft must be replaced.

c)Place the camshaft between centres and with a dial indicator against the centre journal check that the run-out does not exceed 0.002 inch.

d)Check the camshaft gear and thrust plate for wear which will produce excessive end clearance.

e)Check the camshaft running clearance against the dimensions given in specifications. If inspection proves it necessary, remove the camshaft bearing .

f)Inspect the valve tappets for wear to specifications.

4.ASSEMBLY a)Install the thrust plate on the camshaft. b)Fit a new key to the camshaft then press on the camshaft gear to leave a clearance of 0.008”-0.017“ between the gear hub rear face and the thrust plate. Ensure that the thrust plate is located against its abutment shoulder when checking this clearance (Fig.5)

5.INSTALLATION a)Install the valve tappets in their original positions. b)Coat the camshaft and camshaft bearings with clean engine oil. c)Install the camshaft in the crankcase taking care not to damage the bearings and engage the camshaft gear with the crankshaft pinion ensuring that the single timing marks are in register. d)Secure the thrust plate to the crankcase with the bolts and lockwashers and tighten the bolts to the specified torque. e)Invert the engine and install the oil pump. f)Install the front cover. g)Install the valve push rods in their original positions. h)Install the valve rocker arm shaft assembly.